Coating composition, antireflection film, manufacturing method therefor, laminate, and solar cell module

Abstract

Unit (3): R1—Si—O3/2 unit

What is claimed is: 
     
         1 . A coating composition comprising:
 polymer particles having a number-average primary particle diameter of 30 nm to 200 nm;   a siloxane resin which has a weight-average molecular weight of 600 to 6,000, is a siloxane resin including at least one unit selected from units (1), (2), and (3) described below, and has a total mass of the units (1), (2), and (3) being 95% by mass or more of a total mass of the siloxane resin; and   a solvent,   unit (1): R 1 —Si(OR 2 ) 2 O 1/2  unit,   unit (2): R 1 —Si(OR 2 )O 2/2  unit, and   unit (3): R 1 —Si—O 3/2  unit,   in the units (1), (2), and (3), R 1 's each independently represent an alkyl group having 1 to 8 carbon atoms or an alkyl fluoride group having 1 to 8 carbon atoms, R 2 's each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and, in a case where both the units (1) and (2) are included, the alkyl groups having 1 to 8 carbon atoms represented by R 1 's or R 2 's may be identical to or different from each other.   
     
     
         2 . The coating composition according to  claim 1 ,
 wherein a proportion of a mass of the polymer particles in a SiO 2 -equivalent mass of the siloxane resin is 0.1 or more and 1 or less.   
     
     
         3 . The coating composition according to  claim 1 ,
 wherein a concentration of solid contents is 1% by mass to 20% by mass.   
     
     
         4 . The coating composition according to  claim 1 ,
 wherein the solvent is made up of water and an organic solvent, and a content of the organic solvent is 50% by mass or more of a total mass of the solvent.   
     
     
         5 . The coating composition according to  claim 4 ,
 wherein the organic solvent includes an organic solvent having a high boiling point, and a content of the organic solvent having a high boiling point is 1% by mass or more and 20% by mass or less of the total mass of the solvent.   
     
     
         6 . The coating composition according to  claim 1 ,
 wherein the polymer particles are nonionic polymer particles.   
     
     
         7 . The coating composition according to  claim 1 ,
 wherein a pH of the coating composition is 1 to 4.   
     
     
         8 . The coating composition according to  claim 1 ,
 wherein the coating composition further includes an acid, and a pKa of the acid is 4 or less.   
     
     
         9 . The coating composition according to  claim 8 ,
 wherein the acid is an inorganic acid.   
     
     
         10 . An antireflection film which is a cured substance of the coating composition according to  claim 1 . 
     
     
         11 . The antireflection film according to  claim 10 ,
 wherein an average film thickness is 80 nm to 200 nm.   
     
     
         12 . A laminate comprising:
 a base material; and   the antireflection film according to  claim 10 .   
     
     
         13 . The laminate according to  claim 12 ,
 wherein the base material is a glass base material.   
     
     
         14 . A solar cell module comprising:
 the laminate according to  claim 12 .   
     
     
         15 . A laminate comprising:
 a base material; and   an antireflection film formed on the base material,   wherein the antireflection film has holes having a hole diameter of 30 nm to 200 nm in a matrix containing silica as a main component, the number of holes that are opened on an outermost surface of the antireflection film and have a diameter of 20 nm or more is 13 holes/10 6  nm 2  or less, an average transmittance (T AV ) at a wavelength of 380 to 1,100 nm is 94.0% or more, and a pencil hardness measured using a method described in JIS K-5600-5-4 (1999) is 3H or higher.   
     
     
         16 . The laminate according to  claim 15 ,
 wherein an average film thickness of the antireflection film is 80 nm to 200 nm, and a standard deviation σ of film thicknesses is 5 nm or less.   
     
     
         17 . The laminate according to  claim 15 ,
 wherein the base material is a glass base material.   
     
     
         18 . A solar cell module comprising:
 the laminate according to  claim 15 .   
     
     
         19 . A method for manufacturing an antireflection film comprising:
 a step of forming a coating film by applying the coating composition according to  claim 1  onto a base material;   a step of drying the coating film formed by application; and   a step of firing the dried coating film.